| 不同温度条件下冻结兰州黄土单轴试验的CT实时动态监测 |
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| 引用本文： | 赵淑萍,马 巍,郑剑锋,焦贵德.不同温度条件下冻结兰州黄土单轴试验的CT实时动态监测[J].岩土力学,2010,31(Z2):92-97. |
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| 作者姓名： | 赵淑萍 马 巍 郑剑锋 焦贵德 |
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| 作者单位： | （1. 中国科学院寒区旱区环境与工程研究所 冻土工程国家重点实验室，兰州 730000；2. 兰州大学 土木工程与力学学院，兰州 730000 |
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| 基金项目： | 国家自然科学基金资助项目(No. 40971046，No. 40901039)；中国科学院西部行动计划（二期）项目(No. KZCX2-XB2-10)；国家自然科学基金创新群体(No. 40821001)， |
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| 摘 要： | 改进了与CT扫描系统配套使用的三轴仪。改进后三轴仪由控温精度达到±0.1℃的压力罐和加载装置组成，能够实现对冻土力学试验过程真正的CT实时动态监测。对不同温度条件下的冻结兰州黄土单轴压缩过程进行了CT动态扫描， 得到如下结论，应变0～0.7%的阶段，试样发生弹性变形，CT数轻微增大；应变0.7%～6.5%的阶段，开始发生塑性变形，但还没有发生损伤，CT数变化不大；当应变大于6.5%时，试样的CT数明显变小，损伤开始发生，直至应变达到10%时，试样发生破坏，随后CT数也急剧减小。因此，冻结兰州黄土的屈服应变为0.7%，损伤应变临界值为6.5%，破坏应变临界值为10%。另外，温度对试样的CT数也有影响，在-0.6～-1.7 ℃的温度范围内，试样CT数变化具有很明显的规律，即温度越低，CT数越小，在-1.7 ℃和-5 ℃试验条件下CT数变化不大。
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| 关 键 词： | 冻结兰州黄土 CT实时动态监测 损伤应变临界值 破坏应变临界值 |
| 收稿时间： | 2010-11-09 |
CT real-time monitoring on frozen Lanzhou loess at different temperatures and under uniaxial loading |
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| ZHAO Shu-ping,MA Wei,ZHENG Jian-feng,JIAO Gui-de.CT real-time monitoring on frozen Lanzhou loess at different temperatures and under uniaxial loading[J].Rock and Soil Mechanics,2010,31(Z2):92-97. |
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| Authors: | ZHAO Shu-ping MA Wei ZHENG Jian-feng JIAO Gui-de |
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| Institution: | 1. State Key Laboratory of Frozen Soil Engineering, CAREERI, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China; 2. School of Civil Engineering and Mechanics, Lanzhou University, Lanzhou, Gansu 730000, China |
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| Abstract: | The triaxial test apparatus which works together with the CT system was enhanced, including a triaxial pressure pot with ±0.1 ℃ temperature control precision and loading device. Then, a series of CT scanning tests were performed on frozen Lanzhou loess at different temperatures under uniaxial loading condition. And then some conclusions are drawn as follows. When the strain changes in the range of 0-0.7%, the CT number increases lightly. When the strain changes from 0.7% to 6.5%, the CT number is almost unchanged, and plastic strain begin occurs. When the strain exceeds 6.5%, the CT number decrease obviously; and damage begins occurring. When the strain reaches 10%, CT number decreases speedily, and failure in samples occurs. So, as for frozen Lanzhou loess, the yield strain is 0.7%; damage strain critical value is 6.5%; and failure strain critical value is 10%. In addition, temperature also has influence on the CT number. When the temperature changes in the range of -0.6 ℃- -1.7 ℃, lower the temperature is, smaller the CT number will be. The CT number changes little at temperature range of -1.7 ℃ and -5 ℃. |
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| Keywords: | frozen Lanzhou loess CT real-time monitoring damage strain critical value failure strain critical value |
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